Both lungs are covered with miliary shadows

Introduction In the X-ray of the chest of patients with NOx poisoning, the lungs are covered with miliary shadows. Nitrogen oxides include various compounds such as nitrous oxide (N2O), nitric oxide (N0), nitrogen dioxide (NO2), dinitrogen tetroxide (N203), dinitrogen tetroxide (N204), and Nitrous oxide (N205) and the like. Except for nitrogen dioxide, other nitrogen oxides are extremely unstable. When exposed to light, humidity or heat, they become nitrogen dioxide and nitrogen monoxide, and nitric oxide becomes nitrogen dioxide. Therefore, in the occupational environment, several gas mixtures are often referred to as soot (gas), mainly nitrogen monoxide and nitrogen dioxide, and mainly nitrogen dioxide.

Cause

Exposure to nitrogen oxides in various occupational activities, such as making nitric acid or diluting metals with nitric acid; making nitro compounds such as nitro explosives, nitrocellulose, picric acid, diazotization of aniline dyes, and organic matter (such as wood chips, paper) When the flakes are exposed to concentrated nitric acid; the explosion of nitro explosives, nitrogenous substances and nitric acid combustion; the gas generated by satellite launching and rocket propulsion also contains a large amount of nitrogen oxide gas. In the case of electric welding, sub-arc welding, gas cutting and arc illuminating, the high temperature generated can combine oxygen and nitrogen in the air into nitrogen oxides; the exhaust gas discharged from the internal combustion engine of the automobile also contains nitrogen oxides. In addition, some green fodder and grain contain potassium nitrate, which can be fermented under poor ventilation and anoxic conditions to form potassium nitrite and oxygen, and further potassium nitrite becomes nitrous acid. When the fermentation temperature in the warehouse is increased, nitrous acid is decomposed. The formation of nitrogen oxides and water, resulting in "silogas poisoning" of various production processes formed by the smoke, the composition of which is different.

an examination

Related inspection

Pulmonary function examination lung imaging lung examination

Acute nitrogen oxide poisoning mainly damages the target organ to the respiratory system. According to clinical manifestations are divided into:

Acute mild poisoning

Chest tightness, cough, cough, etc., usually accompanied by mild headache, dizziness, weakness, palpitations, nausea, fever, etc. after inhalation of nitrogen oxides for a few hours to 72h incubation period; mild congestion of the conjunctiva and nasopharynx There are scattered dry sounds in the lungs. Chest X-rays show enhanced lung texture or blurred lung texture edges. Blood gas analysis: When breathing air, the arterial oxygen partial pressure can be lower than the expected value of 1.33 ~ 2.66kPa (10 ~ 2OmmHg).

2. Acute moderate poisoning

Have difficulty breathing, chest tightness, increased cough, cough or hemoptysis, often accompanied by dizziness, headache, weakness, palpitations, nausea and other symptoms, and mild purpura. Both lungs have dry sounds or scattered in wet sounds. The total number of white blood cells is increased. Chest X-rays showed reduced lung field transparency, increased lung texture, disorder, and blurred mesh shadows; or partial or scattered patchy shadows, or merged into patchy shadows with blurred edges. Blood gas analysis: When the low concentration oxygen (less than 50%) is absorbed, the arterial oxygen partial pressure can be maintained greater than 8 kPa (6OmmHg).

3. Acute severe poisoning

One of the following clinical manifestations is severe poisoning.

(1) pulmonary edema: respiratory distress, increased cough, cough a lot of white or pink foam, obvious purpura. Both lungs can smell dry and wet. Chest X-rays show patchy shadows of two lungs with low density, blurred edges, or cloud-like shadows of varying sizes, and some merge into large patches. May be associated with complications such as pneumothorax and mediastinal emphysema. Blood gas analysis: In the case of inhalation of high concentration oxygen (greater than 50%), the arterial oxygen partial pressure is less than 8 kPa (60 mmHg).

(2) Coma or suffocation.

(3) Acute respiratory distress syndrome (ARDS).

4. Delayed obstructive bronchiolitis in the inhalation of nitrogen oxide gas, no obvious symptoms of acute poisoning or about 2 weeks after the recovery stage of pulmonary edema, sudden cough, chest tightness, progressive dyspnea, obvious purpura. Both lungs can smell dry and wet or fine wet sound. The chest X-ray shows that both lungs are covered with miliary shadows. Long-term exposure to low concentrations (above the maximum allowable concentration) of nitrogen oxides can cause bronchitis and emphysema.

diagnosis

1. Have a career history (or medical history) of inhaled nitrogen oxides.

2. The clinical manifestations characterized by chemical bronchitis, pneumonia and pulmonary edema occur after a period of exposure to toxicants for a period of hours to 72 hours.

3. Chest X-ray film is consistent with the characteristics of irritating pulmonary inflammation or pulmonary edema.

4. Blood gas analysis results show that the arterial oxygen partial pressure is reduced.

Differential diagnosis

Common other lung examination symptoms:

The clinical manifestations of Q fever, X-ray examination often found a segmental or large-leaf blurred shadow around the lower lobe of the lungs, and the texture of the lungs or bronchi can be thickened and infiltrated, similar to bronchial pneumonia.

In patients with cytomegalovirus pneumonia, chest X-ray and CT are commonly seen in both glassy miliary or nodular changes.

Pulmonary cavity is a common imaging manifestation of lung diseases, especially tuberculosis. With the control of tuberculosis, the proportion of lung cavity caused by other diseases is obviously increased. When the lung cavity is found, it should be checked as soon as possible. Determine the cause so as not to cause misdiagnosis and mistreatment.

Pulmonary edema was blurred and enlarged in the hilars during X-ray examination.

Chest radiograph shows isolated nodules in the lung: lung lesions, X-ray chest radiographs are diffuse miliary or small nodular shadows, but also reticular nodules, may be associated with hilar lymphadenopathy.

The material in this site is intended to be of general informational use and is not intended to constitute medical advice, probable diagnosis, or recommended treatments.